1. Field of the Invention
The invention relates generally to performing communications in a multilateral well that uses an electromagnetic (EM) field generating element to generate an EM current in a formation between a main bore and a lateral bore of the multilateral well.
2. Description of the Related Art
The following descriptions and examples are not admitted to be prior art by virtue of their inclusion in this section.
Tools can be lowered into a well to perform various downhole operations. Some of the tools lowered into a well can include electrical devices, such as sensors, controllers, and so forth. Traditionally, communication with such electrical devices has been achieved using electrical cables run from an earth surface location down the well to the downhole electrical devices. However, deployment of electrical cables may not be feasible across the complete interval to the device or may be difficult in various scenarios, such as in a multilateral well that has one or more lateral bores. In such a scenario, a continuous length of electrical cable may not be possible from the main bore into the lateral bore. However, having to electrically connect discrete segments of an electrical cable downhole is difficult and usually requires that such electrical cable connection be made in the presence of liquids (i.e., such a connection may be generally referred to as a “wet connection”).
To address the above issue, one possible technique of performing electrical communications downhole is by use of inductive couplers. An inductive coupler includes a first inductive coupler portion and a second inductive coupler portion that are placed in close proximity with each other. Current provided in one of the inductive coupler portions induces a corresponding current in the other inductive coupler portion, if the two inductive coupler portions are positioned in close proximity to each other. However, the requirement that inductive coupler portions have to be positioned close to each other for proper operation can increase the complexity of the downhole equipment, since the downhole equipment would have to be provided with appropriate positioning devices to ensure that inductive coupler portions are properly positioned with respect to each other so as to enable them to communicate.